Precast structure and method of construction

ABSTRACT

Precast structures are formed of precast walls fitted between precast posts extending from cast in place footings, prior to the pouring of a slab. During pouring of the slab, anchors may tie together the panels, posts and slab. Precast concrete, tension fabric or traditional roofing members may be added to form a post and beam construction that spans large open areas providing for flexible manufacturing, storage, hangar, office, schools, institutional, or residential interior design features, due to the structural integrity and cost advantages of structures produced using this method of precast construction.

RELATED APPLICATION

This application claims the benefit of the filing date of U.S. Provisional Patent Application No. 61/169,585 filed Apr. 15, 2009, the disclosure of which application is hereby incorporated by reference.

FIELD OF THE INVENTION

The field relates to construction methods using precast concrete elements.

BACKGROUND OF THE INVENTION

Precast panels and posts are known for highway sound barriers and the like. These systems use posts projecting upwards from cement footings as frames for precast panels that are erected between the posts.

U.S. Pat. No. 5,570,549 discloses a known anchoring system. These anchoring systems are costly in both materials and labor costs and do not always prevent structural damage caused by natural disasters.

U.K. Pat. Appl. GB 2,423,533 discloses a process for making a slab for a conservatory. The slab is cast in place and is then fixed to structural members of the conservatory.

U.S. Pat. No. 6,385,933 discloses a method for making precast concrete wall panels and for erecting the precast concrete walls on a slab that was previously cast in place.

U.S. Pat. No. 7,275,348 discloses a precast, prestressed concrete truss and method of manufacture and use in construction of structures that reduces the need for interior columns.

The entirety of the descriptions and drawings of each specification summarized above is incorporated herein by reference for the purpose of providing background.

SUMMARY OF THE INVENTION

A method of construction for structures comprises erecting precast concrete posts in foundation footings, fitting precast concrete panels between each pair of the posts, and then pouring a slab that has an upper slab surface extending a distance beyond a bottom surface of the precast concrete panels and a lower slab foundation surface extending a distance below the bottom surface of the precast concrete panels. In one example, anchors may extend from a surface of the precast concrete panels and from the footings for the posts, and the method includes tying the anchors to the slab or slab foundation portion. For example, the anchors may overlap and tie into reinforcements within the cast in place slab, such as metal reinforcing bars.

A precast structure produced by one example of the method has improved structural rigidity and damage tolerance compared to known construction methods. Surprisingly, the improvement in structural rigidity and damage tolerance with the casting of the slab after erection of the walls reduces costs, labor and construction delays of known methods of construction that require the slab to be cast prior to erecting walls and the roof. By inserting isolating and/or expansion barriers between panels and posts or between panels and the slab, vibrations may be isolated and thermal expansion may be addressed.

By tying together the posts, panels, slab, and roofing elements, an integrated structural framework is formed that has exceptional rigidity and damage tolerance from earth quakes, storms and blasts.

Surprisingly, the new construction method requires no temporary bracing, pour back strips and the like as required by known construction methods, resulting in a reduction of costs of materials and labor.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings are merely examples of precast structures and methods of construction, and the claims are not limited to the features represented in the drawings.

FIG. 1 illustrates an example of a completed precast concrete structure, having footings and posts extending upwardly from the footings.

FIG. 2 illustrates an example of a “waffle” panel from an interior elevation review.

FIG. 3 illustrates an example of panels being placed between the posts, with or without an expansion membrane.

FIG. 4A illustrates a detailed view of panels having an expansion membrane inserted between the panel and the post.

FIG. 4B illustrates a detailed view of panels and a corner post without an expansion membrane.

FIG. 5 illustrates an example of a method including pouring a slab after the erection of the posts, panels, and a roof

FIG. 6A illustrates an example of a connection between two roof panels and a beam.

FIG. 6B illustrates an example of a connection between two stacked “waffle” panels.

FIGS. 6C and 6D illustrate examples of roofing panels anchored to walls.

FIGS. 7A and 7B illustrate an example of a precast concrete panel having anchors extending from an interior surface of the precast concrete panel.

FIG. 8A illustrates a top plan view of an example of a detailed view of anchors extending from a footing overlapping reinforcing bars in the slab.

FIG. 8B illustrates a side, interior view of the example of FIG. 8A.

FIG. 9 illustrates an example of panels with openings.

FIG. 10 illustrates an example of a sloped roof

FIG. 11 illustrates another example of a precast structure.

FIGS. 12A and 12B illustrate yet another example of a precast structure.

DETAILED DESCRIPTION OF THE INVENTION

The examples described and drawings rendered are illustrative and are not to be read as limiting the scope of the invention as it is defined by the appended claims.

The following examples describe a precast structure and a method for construction of a precast structure, but the invention is not limited to the specific examples described. Instead, it should be understood that the features in the examples and the methods disclosed are merely illustrative. The claims that eventually issue should be interpreted in light of the specification, but the claims should not be limited by the description and drawings of the examples presented. The illustrations use the same illustration numbers to identify identical and similar features.

A method of construction for structures comprises erecting precast concrete posts in foundation footings, fitting a precast concrete panel between each pair of the posts, and pouring a slab. The slab is poured after the step of fitting each of the precast concrete panels between the posts. The step of pouring the slab ties the slab to the posts and panels providing a surprising and unexpected integrity and strength of the structure. The slab is poured with an upper slab surface extending a depth above a bottom surface of the precast concrete panel and having a lower slab foundation surface extending a distance below the bottom surface of the precast concrete panel. In one example, a plurality of anchors extend from a surface of the precast concrete panels. The plurality of anchors extend from the surface of the precast concrete panels such that the plurality of anchors extend into the slab after the step of pouring is completed, further locking the panels to the slab. Such a structure is much more resistant to damage by explosion, earthquake, impact or the like.

In one example, at least one anchor extends from a footing of the precast concrete posts, and the method includes tying the at least one anchor from each of the footings of the precast concrete posts to the slab or slab foundation portion after the step of pouring. Thus the footings are tied into the slab. At least one anchor from each of the footings of the precast concrete posts may overlap and tie into reinforcements within the slab after the step of pouring, for example. The plurality of anchors extending from the surface of the precast concrete panels may be comprised of metal reinforcing bars. For example, metal reinforcing bars may be the normal reinforcing bars internal to the precast concrete panels and reinforcing the structure of the precast concrete panels. Then, these metal reinforcing bars may extend, exposed, from the bottom portion of the precast concrete panels, at least one-third of a meter, more preferably at least one meter. Structures prepared according to examples of the method have a unique structure and unexpectedly improved damage tolerance and strength compared to conventional structures. The pouring of the slab/foundation after the positioning of the precast walls allows the entire structure to be tied together in situ during setting of the slab/foundation.

FIG. 1 illustrates an example of a structure 1, with the surrounding earth removed, including precast concrete panels 20. Panels 20 are inserted between posts 30 or corner posts 31, 33, and the panels 20 may have anchors 22 as illustrated in FIG. 7, extending outwardly from an interior surface 24 of the panels 20. The posts 30, and the footings 10 poured to support the posts, illustrated in more detail in the example of FIG. 2, are the supporting structures for a building, and beams 40, 41 tie the posts 30 together, forming an integrated structural support frame for the building. Precast concrete panels 20, such as the “waffle” panels of FIG. 2 may be fit in between into the posts 30 to further increase the structural rigidity of the structure 1, as illustrated in FIG. 3, for example. An isolation and/or expansion barrier 26, such as an elastic membrane, adhesive layer, gel, foam or felt, may be inserted between the panels 20 and the posts 30 to isolate the panels 20 from vibrations and/or heat transfer and/or expansion mismatch between the panels 20 and the posts 30, as illustrated in the example of FIG. 4. In one example, the panel tongue 21 is embedded at least 4 inches into a recess formed in the post 30. Isolating the panels 20 from the posts 30, 31, 33 may be used in buildings that require protection from blasts and may reduce damage to the structure during earthquakes, for example. In another example, the barrier 26 may allow for expansion and contraction due to a mismatch in the thermal coefficient of expansion or temperature differences between panels 20 and posts 30. The posts 30 may be cast into the footings 10.

After erecting the posts 30 on or in the footings 10, the panels 20 are inserted, with or without a barrier 26, and beams 40 and roofing panel 50 may be added to complete the structural components above grade. Then, the slab 60 may be poured, as illustrated in the example of FIG. 5, such as by using a concrete pump 61 and hoses 63 or directly from cement trucks, with or without a pump to assist. By pouring the slab 60 after erecting the panels 20 and the posts 30, surprising and unexpected structural integrity and time and cost savings are realized over any known system of building construction. While the outward appearance of a structure 1 fabricated in this way appears unchanged, the degree of interconnection between the precast panel anchors 22 and/or post anchors 32 and the poured in place slab 60, as illustrated in FIGS. 7A and 7B and FIGS. 8A and 8B, is unmatched in any known construction method.

The footings 10 may include pilings that extend downward into the ground a distance sufficient to withstand flooding and erosion caused by hurricane force winds and tsunamis, such as ten feet in one example, making the structure 1 suitable for marinas, such as for dry dock boat storage structures, for example. The post and beam construction can provide a space suitable for use as an aircraft hangar, a gymnasium, a manufacturing plant, flexible office space, housing, schools and other institutional buildings to name a few of the structures that would benefit from the structural integrity and cost advantages of this method of construction.

In FIG. 6A, two panels 50 are joined to a beam 40 by a coil rod 41 inserted through a precast or machined hole. The coil rod 41 has a horseshoe washer 43 placed on either end and coil nuts 42 secure the panels 50 to the beam 40. A channel 46 is in fluid communication with the hole surrounding the coil rod 41 and provides a means for filling the hole and channel 46 with a pourable grout, isolating the coil rod 41 from the precast concrete panel 50. In FIG. 6B, a pair of stacked panels 20, forming a wall between two posts (not shown), are secured together with a coil rod 92 inserted through a sleeve 96, such as a sleeve made of PVC, extending through a hole precast or machined through the panels 20. A pair of horseshoe washers 91 and coil nuts 94 are secured on the ends of the coil rod 92, fastening the two panels 20 together. In FIG. 6C, a panel 50 is secured to a portion of the wall 70 using a coil insert 71 to anchor one end of a coil rod 72 to the wall portion 70. The opposite end of the coil rod 72 extends through a hole in the panel 50 and is secured with a horseshoe washer 73 and a coil nut 74. A sleeve 76, such as a sleeve made of PVC, isolates the coil rod 72 from the precast concrete panel 50. In FIG. 6D, a penal 50 is secured to a header 80 of a wall using a coil insert 81 to anchor one end of a coil rod 82 to the header 80. The opposite end of the coil rod 82 extends through a hole in the panel 50 and is secured with a horseshoe washer 83 and a coil nut 84. A sleeve 86, such as a sleeve made of PVC, isolates the coil rod 82 from the precast concrete panel 50. An expansion barrier and/or sealant material may be inserted between the panels 20, 50, beams 40, and wall portions 70, 80 of the structure 1 to minimize or eliminate leakage and gaps.

In the example of FIGS. 7A and 7B, anchors 22 extend from the surface 24 of the precast “waffle” concrete panel 20 tying the slab to the precast concrete panel 20. FIGS. 8A-8B illustrate a detailed view of the slab 60 anchors 32 extending from the concrete posts 30. Thus, the anchors 22, 32 of the precast concrete panels 20 and posts 30, 31, 33 serve to tie the slab 60 to the foundations 10 for the posts 30. In the example of FIG. 7B, the top 65 of the slab 60 extends above the bottom 27 of the panel, and the bottom 67 of the foundation portion 69 of the slab 60 extends below the precast concrete panels 20.

An isolation and/or expansion barrier 66 is illustrated in FIG. 8A, such as an elastic membrane, adhesive layer, gel, foam or felt. This barrier 66 isolates the slab 60 from the posts 30 and the panels 20. The anchors 22, 32 serve to tie together the slab 60, the posts 30 and the panels 20 to impart structural rigidity and damage tolerance to the structure. The anchors 22, 32 may be bands, straps, bars, bent bars, wire mesh and the like and may be protected from corrosion by choice of materials or anti-corrosive coatings. The anchors 22, 32 may be tied into reinforcements of the poured in place concrete slab 60, such as rebar, wire mesh or other reinforcements. The unique structural integrity of the structure makes it storm resistant such as resistant to missile impact according to federal, state and local certifications, including Miami-Dade County missile impact standards for Class 4 hurricanes and better.

FIG. 9 illustrates an example of customizable openings in precast “waffle” panels 26, 27, such as a door 28 or louvered vents 29. FIG. 10 illustrates how the pitch of a roof may be managed by adjusting the height of the beams 40 mounted on the posts 30 and the mounting height on the corner posts 31, 33, using precast panels 50. A “flat” roof is shown that has a pitch toward the rear of the structure 1.

A jig may be used to drill holes for the footings 10 and to cast in place the footings 10 with the reinforced concrete precast posts 30 cast into the footings 10 and properly spaced and aligned one to the other.

In FIG. 11, a precast structure is illustrated that combines the precast construction methods with a roofing structure comprising a structural peak 112 on either end, arched truss structures 114 and tension fabric 116 mounted on the arched truss structures 114. The arched truss structures 114 serve as compression members, and the tension fabric 116 serves as a tensile membrane, allowing large, uninterrupted spans to be provided by the structure 100 made with walls of precast, reinforced concrete panels 20. FIGS. 12A and 12B illustrate yet another embodiment of a structure utilizing tension fabric 116 on arcuate I-beam structural members 118 spanning a wide A uninterrupted space. For example a width A of 180 feet (54.9 meters) may be spanned by such a roofing structure supported by walls of precast concrete construction mounted and integrally cast into place with the slab, as disclosed previously. In the example of FIGS. 12A and 12B, columns 120 are formed or cast in place that are wider at the base than at the top. One or more precast panels 122 are inserted between each pair of columns 120 to form walls prior to pouring the slab 60. The distance C between columns 120 may be ten to twenty feet (about 3.05 meters to 6.1 meters), for example. The length of the structure is not limited. The maximum height B of the arched roof is determined by the width A and the arcuate curvature of the beams 118. The tension fabric 116 provides a tensile force pulling the walls inward, while the beams 118 exert a compressive force forcing the walls outward. The combination of compressive and tensile forces provides a balance that is within the tolerance of the wall structures comprised of the columns 120 and panels 122. For example a 180 foot (54.9 meters) width A may have a maximum height B of the arched roof of 50 feet (15.2 meters), in one example.

Alternative combinations and variations of the examples provided will become apparent based on this disclosure. It is not possible to provide specific examples for all of the many possible combinations and variations of the embodiments described, but such combinations and variations may be claims that eventually issue. 

1. A method of construction for structures comprises: erecting a plurality of precast concrete posts; fitting a precast concrete panel between a pair of the plurality of posts; and pouring a slab, after the step of fitting, the slab having an upper slab surface extending a depth above a bottom surface of the precast concrete panel and having a lower slab foundation surface extending a distance below the bottom surface of the precast concrete panel.
 2. The method of claim 1, wherein a plurality of anchors extend from a surface of the precast concrete panels and the plurality of anchors extend from the surface of the precast concrete panels such that the plurality of anchors extend into the slab after the step of pouring is completed.
 3. The method of claim 2, wherein at least one anchor extends from a footing for supporting one of the pair of the plurality of precast concrete posts, and tying the at least one anchor from the footing of the precast concrete posts to the slab or slab foundation portion after the step of pouring.
 4. The method of claim 3, wherein the at least one anchor from each of the footings of the precast concrete posts overlap and tie into reinforcements within the slab after the step of pouring.
 5. The method of claim 3, wherein the plurality of precast concrete posts have reinforcing bars and the reinforcing bars extend exposed from a lower portion of the plurality of precast concrete posts are inserted into the footing during the step of erecting, prior to setting of a cementitious material of the footing.
 6. The method of claim 2, wherein the plurality of anchors are reinforcing bars internal to the precast concrete panels, reinforcing the structure of the precast concrete panels, and the reinforcing bars extend exposed from the surface of the precast concrete panels at least one-third of a meter.
 7. The method of claim 6, wherein the metal reinforcing bars extend exposed from the surface of the precast concrete panels at least one meter.
 8. A structure manufactured according to the method of claim 1, comprising: a plurality of posts; a plurality of precast concrete panels, each of the plurality of precast concrete panels being inserted between two of the plurality of posts, and each of the plurality of precast concrete panels comprise at least one anchor extending beyond a surface of each of the plurality of precast concrete panels; and a plurality of footings, each of the plurality of footings supporting one of the plurality of precast concrete posts; and a poured slab, such that the at least one anchor of the plurality of precast concrete panels are tied into the slab.
 9. The structure of claim 8, wherein each of the plurality of footings has at least one anchor extending from a surface of each of the plurality of footings such that the anchor is tied into the slab.
 10. The structure of claim 9, further comprising a plurality of beams, and the beams tie the posts together, forming an integrated structural support frame for the structure.
 11. The structure of claim 1, wherein the plurality of precast concrete panels include a waffle pattern.
 12. The structure of claim 1, further comprising an expansion barrier inserted between each of the plurality of panels and the posts.
 13. The structure of claim 12, wherein the expansion barrier comprises an elastic membrane.
 14. The structure of claim 12, wherein the expansion barrier comprises an adhesive layer.
 15. The structure of claim 12, wherein the expansion barrier comprises a gel.
 16. The structure of claim 12, wherein the expansion barrier comprises a foam.
 17. The structure of claim 12, wherein the expansion barrier comprises a felt.
 18. The structure of claim 12, wherein each of the plurality of panels comprises a panel tongue, and the panel tongue is embedded at least 4 inches into a recess formed in the post.
 19. The structure of claim 8, further comprising a coil rod, wherein the coil rod is inserted through the precast or machined hole.
 20. The structure of claim 19, further comprising a beam, wherein the coil rod comprises a horseshoe washer placed on either end of the coil rod, and a coil nut secures one or more of the plurality of panels to the beam.
 21. The structure of claim 8, further comprising a channel in fluid communication with the hole surrounding the coil rod, providing a means for filling the hole and channel with a pourable grout.
 22. The structure of claim 8, wherein a pair of the plurality of panels are stacked one over the other between the two of the plurality of posts, forming a wall between the two of the plurality of panels. 